1. Field of the Invention
The present invention relates to an OSI multilayer management system.
2. Description of the Related Art
Based on the ITU-T Recommendation M.3010, conventional OSI multilayer management systems have been divided into and modeled after a business management layer, a service management layer, a network management layer, a device management layer, and a device layer. Generally, each of the layers comprises a manager and an agent. The manager requests the agent to provide a service, and the agent provides the service to the manager. Fault information detected by the agent and changes of attributes are reported as an event notification from the agent to the manager.
FIG. 2 of the accompanying drawings shows a conventional OSI multilayer management system. As shown in FIG. 2, an upper-layer agent 502 requested to provide a service by an upper-layer manager 501 accesses an upper-layer MIB (Management Information Base) 503 to perform a management service function. If necessary, the upper-layer agent 502 may issue a new service request to a manager in a layer immediately therebelow, i.e., a lower-layer manager 505. The management system of each layer has unique management information model information. In order to do a service between layers, a managed-object correspondence information converter 504 is defined for relating managed objects to each other between the layers. The managed-object correspondence information converter 504 corresponds to an ICF (Information Converting Function) prescribed in the figure V-2/M.3010 on page 61 of the ITU-T Recommendation M.3010.
When a managed object stored in the upper-layer MIB 503 needs to access a managed object stored in lower-layer MIBs 507 managed by the lower-layer manager 505, the managed-object correspondence information converter 504 identifies one of the lower-layer MIBs 507 whose upper-most instance in an inclusion relation corresponds to the managed object, and transmits information representative of such correspondence and a management operation requested by the upper-layer manager 501 to the lower-layer manager 505.
Based on the upper-most instance in an inclusion relation of the lower-layer MIB 507 which has been identified by the managed-object correspondence information converter 504, i.e., the information indicative of which one of the lower-layer MIBs 507 the request has been directed to, and the information indicative of what type of operation is to be effected on the identified lower-layer MIB 507, the lower-layer manager 505 analyzes the information to determine what operation is requested by the request with respect to which managed-object instance of the lower-layer MIBs 507 managed by which one of lower-layer agents 506. Based on the determined results, the lower-layer manager 505 transmits a request with respect to the managed-object instance and the management operation stored in the lower-layer MIB 507 to the lower-layer agent 506.
In response to the request transmitted from the lower-layer manager 505, the lower-layer agent 506 carries out the management operation on the managed-object instance stored in the lower-layer MIB 507.
When the management operation is finished in the lower-layer MIB 507, the lower-layer agent 506 transmits an operation response result to the lower-layer manager 505, which then determines which one of the lower-layer MIBs 507 the operation response result has come from, i.e., one of the lower-layer MIBs 507 whose upper-most instance in an inclusion relation corresponds to the operation response result. The lower-layer manager 505 transfers the managed-object information of the managed object of the determined lower-layer MIB 507 and a response result which has been converted to a type of data that can be interpreted by the upper-layer agent 502 and the upper-layer manager 501 corresponding to the determined managed object, to the managed-object correspondence information converter 504.
Based on the received response information, the managed-object correspondence information converter 504 locates a corresponding managed object in the upper layer, and transfers the response information through the upper-layer agent 502 to the managed object stored in the upper-layer MIB 503 which has issued the operation request. The managed object stored in the upper-layer MIB 503 effects internal processing using the response information, transmits a processed result through the upper-layer agent 502 to the upper-layer manager 501, and finishes the processing.
An event notification from the lower layer to the upper layer is processed in a manner similar to the above processing of the request. Specifically, when an event notification is issued from the lower-layer agents 506 to the lower-layer manager 505, the lower-layer manager 505 determines, from the managed-object instance of the lower-layer MIB 507 which has notified an event, which one of the lower-layer MIBs 507 corresponds to the event notification, i.e., the upper-most instance in an inclusion relation with respect to the managed-object instance which has issued the event notification, converts the contents of the notification of the managed-object instance of the lower-layer MIB 507 which has notified the event to a type of data which can be interpreted by the upper-layer agent 502 or the upper-layer manager 501, and notifies the managed-object correspondence information converter 504 of the event. The managed-object correspondence information converter 504 determines which one of the managed objects in the upper layer corresponds to the managed-object instance which has issued the event notification, and indicates the result to the upper-layer agent 502 thereby to update the data in the upper-layer MIB 503 and report the event notification to the upper-layer manager 501.
In the conventional OSI multilayer management system shown in FIG. 2, the managed-object correspondence information converter 504 positioned in the upper layer has to recognize at all times the relationship between the lower-layer manager 505 and the managed-object instances of the upper-layer agent 502, and the lower-layer manager 505 positioned in the lower layer has to recognize at all times what operation has to be actually effected on which managed-object instance stored in which lower-layer MIB 507 by the upper-most managed-object instance in an inclusion relation of the lower-layer MIB 507 designated from the managed-object correspondence information converter 504 and its operation request, and has to convert the operation request.
According to the ITU-T Recommendation M.3010, a range to be managed is divided into a hierarchical system of layers for the purpose of making the managers and agents functionally independent of each other, as shown in FIG. 1 of the accompanying drawings. For actual installations, however, an application program has to be developed in which upper and lower layers recognize each other at all times, and changes in the definition of managed objects in the upper or lower layer and the specifications of operations greatly affect the upper and lower layers. In the conventional system, the managed-object correspondence information converter 504 converts a managed object with respect to which an operation request has been issued from the upper-layer agent 502 to the upper-most instance in an inclusion relation of a lower-layer MIB 507, and the lower-layer manager 505 specifies a managed-object instance with respect to which the operation request is to be actually applied, and converts the operation request to a type of data which can be interpreted by the managed object that is to be actually operated. Since such a complex double conversion process is required, a large processing burden is imposed on the managed-object correspondence information converter 504 and the lower-layer manager 505, resulting in a performance problem.
The system has inherent interfaces used as an interface between the upper-layer agent 502 and the managed-object correspondence information converter 504 and an interface between the lower-layer manager 505 and the managed-object correspondence information converter 504. For the managed-object correspondence information converter 504, it has been necessary to fabricate a software program in which respective interfaces with the upper and lower layers are defined. Since these interfaces are not common in nature, there has been a problem in that the software program cannot be diverted in the same layer.